I personally would need a huge price drop in the thing and/or the availability of lots of cheap used ones before I get one.
I think we could probably collectively come up with pre-obd2 instrumentation options. With respect to Yoshi, many people driving pre-obd2 cars by definition can't afford (or don't want to spend the money for) a MID.
One thing I've been thinking about is simply a datalogging DMM. You could use it to monitor/graph a single sensor variable, such as MAP. It wouldn't translate directly into MPG, but would still be very useful for testing or commuting, once you established baseline instant/average values. Essentially a digital, recordable vacuum gauge. That's the simplest thing I can think of.
I tried to find the Metro conditions when fuel cutoff occurs, but couldn't.
I'm guessing that's what you're seeing, but it would be nice to be able to compare it to when the car is "officially" supposed to be doing it.
It makes sense: If the car were still in closed loop when the injector shuts off, the computer would probably have a hissy fit because the O2 sensor information would be showing a value very definitely non-stoich. By flipping into open loop, it's basically saying: ignore the O2 sensor until I tell you otherwise.
Why does the ScanGauge need to know the size of the engine? I know it has already been explained by others on this site, but I want Ron to say it.
Does the SG-I have fuzzy logic that learns the cars behavior? The main question being, I take it from rental to rental and adjust the engine size, and then bring it back to the 'Teg. Does the engine displacement and injector pulse calculate MPG, or does the size of the fuel tank figure into the equation?
BeeUU, I've already wrapped up the interview (will finish the write-up this week, or early next), but you can get his email from the SG website if you want to send questions directly.
Rh: no fuzzy logic. The manual adjustment factor is how it learns. Ron said: "You need to set the engine and fuel tank size for each vehicle. To get the best absolute accuracy, you need to go through a tank of gas, but it should be within 10% for gas and 20% for diesel even before the adjustment."
10% sounds pessimistic to me. I don't think mine was ever more than 4 or 5% off before I used the adjustment feature.